Improvement in hydraulic elevators



UNITED STATES PATENT OFFICE..

DANA BIOKFOBD, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN HYDRAULIC ELEVATORS.

Specification forming part of Letters Patent No. 51,129, dated November28, 1865.

To all whom it may concern:

Be it known that I, DANA BIoKEoED, of Boston, in the county of Suffolkand State of Massachusetts, have invented a new and useful Elevator forRaising Weights or Bodies or Articles of Various Kinds from one Level orPosition to Another or Higher one 5 and I do hereby declare the same tobe fully described in the following specitication,and represented in theaccompanying drawings, of which- Figure l. is a front elevation, andFig. 2 a vertical section of it. Fig. 3 is a horizontal section of itsvalve-chest and air-conduits.

In the said drawings, A A denotes two vertical cylinders projectingupward from a baseplate, B, and having a piston, O, in each of them.These cylinders are open at their upper ends. Their piston-rods a a areconnected by a cross-head or bar, Z),which is furnished with verticalguides, c c, applied to the posts of a frame, D. A platform, E, issuspended from the cross-bar l) and between the two cyl inders.

A pipe, E', connects the two cylinders at their lower parts and opensinto both of them. The said pipe also has an opening, d, leading into achamber, e, which, by a passage or port, h, opens into a valve-chamber,f. The said chamberf also opens by a port, i, into a chamber, g, whichcommunicates freely with the eX- ternal atmosphere. A chambered valve,F, is arranged in the chamber f so as to operate with the ports h Apipe, l", serves to conduct air from an ainforcin g pump or il sequivalent into the valve-chambery.

Vhen the port his uncovered bythe valve the air will pass into thecylinders and below their pistons, and byits pressure upward against thelatter will force them upward and cause the platform to be lifted to ahigher position.

On moving valve F over the two ports It t' the compressed air Within thecylinders will escape into the atmosphere and allow the pistons and theplatforms to fall to their lowest positions.

' A modification of my apparatus, or another mode in which l havecontemplated the application of the principle thereof, may he thusdescribed Instead of having rods to the pistons and a cross-headconnecting them, there may be wire ropes or theirequivalen ts, with oneend attached to the piston, then passing over guide-pulleys placed atthe top of the cylinders and con meeting at the other end with theplatform or spinner-frame. In this case the valve-chest E will be placedat the top, and the compressed air or liquids will be let in there, andthe pistous forced down, in order to raise the platform; or, by passingthe rope over the top pulleys and from them to another set at thebottom, the air or its equivalent can be let in as in the tirst case,and operate the saine.

What l claim as my invention, and wish to secure by Letters Patent, is-

The cylinders A,the frame b, the rods a, the platform E, the valve-chestE', and guides c, or their equivalents, all arranged and operated as andfor the purposes described -and set forth in the foregoing descriptions.

DANA BICKFORD.

Witnesses R. H. EDDY, F. P. HALE, J r.

